Nissan Pathfinder (2008 year). Manual - part 381

CYLINDER HEAD

EM-211

< ON-VEHICLE REPAIR >

[VK56DE]

Push the valve stem to the combustion chamber side, and remove the valve.
• Identify the installation positions, and store them without mixing them up.

Remove the valve oil seal using Tool.

Replace the valve seat if necessary. Refer to

EM-212, "Inspection After Disassembly"

Replace the valve guide if necessary. Refer to

EM-212, "Inspection After Disassembly"

10. Remove the spark plug tube, as necessary.

• Remove the spark plug tube out of the cylinder head using suitable tool.

CAUTION:

• Do not damage the cylinder head.
• Do not remove the spark plug tube unless absolutely necessary. Once removed, the spark plug

tube will be deformed and cannot be reused.

ASSEMBLY

Install the valve guide if necessary. Refer to

EM-212, "Inspection After Disassembly"

Install the valve seat if necessary. Refer to

EM-212, "Inspection After Disassembly"

Install the valve oil seal using Tool.

• Apply new engine oil on the new valve oil seal joint and seal

lip.

• Install the valve oil seal to the specified height "H".

Install the valves in their original position.

Install the valve spring seats.

Install the valve springs.
• Install the narrow pitch end (paint mark side) to the cylinder

head side.

Install the valve spring retainers.

Tool number

: KV10107902 (J-38959)

WBIA0478E

Tool number

: KV10115600 (J-38958)

Height "H" (without valve spring installed)

Intake and exhaust

: 14.3 - 14.9 mm (0.563 - 0.587 in)

WBIA0490E

SEM085D

EM-212

< ON-VEHICLE REPAIR >

[VK56DE]

CYLINDER HEAD

Install the valve collet using Tool.

CAUTION:

When working, take care not to damage valve lifter holes.

Install the valve lifters.
• Install the removed parts in their original locations.
• If installing new lifters, select the correct size lifter for proper valve clearance. Refer to

EM-212, "Inspec-

tion After Disassembly"

10. Install the spark plug tube if necessary, following the procedure below.

Remove any old liquid gasket adhering to the cylinder-head spark plug tube hole.

Apply liquid gasket to area within approximately 12 mm (0.47 in) from the edge of the spark plug tube
press-fit side.
Use Genuine RTV Silicone Sealant or equivalent. Refer to

GI-26, "Recommended Chemical Prod-

ucts and Sealants"

Press-fit the spark plug tube to the specified height “H” using
suitable tool.

CAUTION:

• When press-fitting, take care not to deform the spark plug

tube.

• After press-fitting, wipe off any liquid gasket protruding

onto the cylinder-head upper face.

11. Install the spark plugs.

Inspection After Disassembly

INFOID:0000000001282036

CYLINDER HEAD DISTORTION

Remove any oil, scale, gasket, sealant and carbon deposits from the cylinder head surface.

CAUTION:

Do not allow any debris to enter the oil or coolant passages.

Measure the bottom surface of the cylinder head for distortion in
six directions as shown, using suitable tools.

• If measurement exceeds the limit, replace the cylinder head.

VALVE DIMENSIONS

Tool number

: KV10116200 (J-26336-A)

: KV10115900 (J-26336-20)

: KV10109220 (

—

)

WBIA0578E

Standard press-fit height “H”

:38.4 - 39.4 mm
(1.512 - 1.551 in)

KBIA1248E

Standard

: 0.03 mm (0.0012 in)

Limit

: 0.1mm (0.004 in)

PBIC0075E

CYLINDER HEAD

EM-213

< ON-VEHICLE REPAIR >

[VK56DE]

• Check the dimensions of each valve. Refer to

EM-248, "Standard

and Limit"

• If the dimensions are out of the standard, replace the valve.

VALVE GUIDE CLEARANCE

Valve Stem Diameter

Measure the diameter of the valve stem using suitable tool.

Valve Guide Inside Diameter

Measure the inside diameter of the valve guide using suitable tool.

Valve Guide Clearance

• (Valve guide clearance) = (Valve guide inside diameter) – (Valve stem diameter).

• If the calculated value exceeds the limit, replace valve and/or valve guide. When the valve guide must be

replaced, Follow the "VALVE GUIDE REPLACEMENT" procedure.

VALVE GUIDE REPLACEMENT

When the valve guide is removed, replace it with an oversized (0.2 mm, 0.008 in) valve guide.

SEM188A

Standard

Intake

: 5.965 - 5.980 mm (0.2348 - 0.2354 in)

Exhaust

: 5.955 - 5.970 mm (0.2344 - 0.2350 in)

SEM938C

Standard

Intake and Exhaust

: 6.000 - 6.018 mm (0.2362 - 0.2369 in)

Valve guide clearance:

Standard

Intake

: 0.020 - 0.053 mm (0.0008 - 0.0021 in)

Exhaust

: 0.030 - 0.063 mm (0.0012 - 0.0025 in)

Limit

Intake

: 0.08 mm (0.0031 in)

Exhaust

: 0.09 mm (0.0035 in)

EM-214

< ON-VEHICLE REPAIR >

[VK56DE]

CYLINDER HEAD

To remove the valve guide, heat the cylinder head to 110

130

C (230

to 266

F) by soaking it in heated oil.

Remove the valve guide using suitable tool.

CAUTION:

Cylinder head contains heat. When working, wear protec-
tive equipment to avoid getting burned.

Ream the cylinder head valve guide hole using suitable tool.

Heat the cylinder head to 110

to 130

C (230

to 266

F) by

soaking it in heated oil.

Press the valve guide from the camshaft side to the dimensions
as shown.

CAUTION:

Cylinder head contains heat. When working, wear protec-
tive equipment to avoid getting burned.

SEM008A

SEM931C

Valve guide hole diameter:

Standard

Intake and exhaust

: 9.975 - 9.996 mm (0.3927 -
0.3935 in)

Oversize (service)

Intake and exhaust

: 10.175 - 10.196 mm (0.4006
- 0.4014 in)

SEM932C

SEM008A

KBIA2530E

CYLINDER HEAD

EM-215

< ON-VEHICLE REPAIR >

[VK56DE]

Ream the cylinder head valve guide using suitable tool.

VALVE SEAT CONTACT

• After confirming that the dimensions of the valve guides and valves

are within specifications, perform this procedure.

• Apply prussian blue (or white lead) onto the contacting surface of

the valve seat to check the condition of the valve contact on the
surface.

• Check if the contact area band is continuous all around the circum-

ference.

• If not, grind to adjust the valve fit and check again. If the contacting

surface still has NG conditions even after the re-check, replace the
valve seat.

VALVE SEAT REPLACEMENT

When the valve seat is removed, replace it with oversized (0.5 mm, 0.020 in) valve seat.
1.

Bore out the old seat until it collapses. Boring should not continue beyond the bottom face of the seat
recess in the cylinder head. Set the machine depth stop to ensure this.

Ream the cylinder head recess diameter for service valve seat.

• Be sure to ream in circles concentric to the valve guide center.
• This will enable valve seat to fit correctly.

Heat the cylinder head to 110

to 130

C (230

to 266

F) by

soaking it in heated oil.

Cool the valve seats well with dry ice. Force fit the valve seat into the cylinder head.

CAUTION:

• Avoid directly touching cold valve seats.
• Cylinder head contains heat. When working, wear protective equipment to avoid getting burned.

Valve guide hole diameter:

Intake and exhaust

: 6.000 - 6.018 mm (0.2362
- 0.2369 in)

SEM932C

SBIA0322E

Oversize [0.5 mm (0.020 in)] (Service):

Intake

: 38.500 - 38.516 mm (1.5157 - 1.5164 in)

Exhaust

: 32.700 - 32.716 mm (1.2874 - 1.2880 in)

SEM795A

SEM008A

EM-216

< ON-VEHICLE REPAIR >

[VK56DE]

CYLINDER HEAD

Finish the seat to the specified dimensions using suitable tool.
Follow the "VALVE SEAT CONTACT" procedure.

CAUTION:

When using valve seat cutter, firmly grip the cutter handle
with both hands. Then, press on the contacting surface all
around the circumference to cut in a single drive. Improper
pressure on the cutter or cutting many different times may
result in stage valve seat.

Grind to obtain the dimensions indicated as shown.
• Using compound, grind to adjust valve fitting.

Check again for normal contact. Follow the "VALVE SEAT CONTACT" procedure.

VALVE SPRING SQUARENESS

• Set try square along the side of valve spring and rotate the spring.

Measure the maximum clearance between the top face of spring
and try square.

• If measurement is not within specifications, replace the valve

spring.

VALVE SPRING DIMENSIONS AND VALVE SPRING PRESSURE LOAD

SEM934C

KBIA2531E

KBIA2544E

Limit

: Less than 2.2 mm (0.087 in)

PBIC0080E

CYLINDER HEAD

EM-217

< ON-VEHICLE REPAIR >

[VK56DE]

• Check the valve spring pressure at the specified spring height.

• If measurement is not within specifications, replace the valve spring.

Standard:

Intake and exhaust

Free height:

50.58 mm (1.9913 in)

Installation height:

37.0 mm (1.457 in)

Installation pressure:

165.8 - 187.0 N (16.9 -
19.1 kg, 37- 42 lb)

Height during valve open:

28.2 mm (1.110 in)

Load with valve open:

314.8 - 355.0 N (32.1 -
36.2 kg, 71 - 80 lb)

SEM113

EM-218

< REMOVAL AND INSTALLATION >

[VK56DE]

ENGINE ASSEMBLY

REMOVAL AND INSTALLATION

ENGINE ASSEMBLY

Removal and Installation

INFOID:0000000001282037

WARNING:

• Situate vehicle on a flat and solid surface.
• Place chocks at front and back of rear wheels.
• For engines not equipped with engine slingers, attach proper slingers and bolts described in PARTS

CATALOG.

CAUTION:

• Always be careful to work safely, avoid forceful or uninstructed operations.
• Do not start working until exhaust system and engine coolant are cooled sufficiently.
• If items or work required are not covered by the engine section, follow the applicable sections.
• Always use the support point specified for lifting.
• Use either 2-point lift type or separate type lift. If board-on type is used for unavoidable reasons,

support at the rear axle jacking point with transmission jack or similar tool before starting work, in
preparation for the backward shift of center of gravity.

• For supporting points for lifting and jacking point at rear axle, refer to

GI-43, "Garage Jack and

Safety Stand"

REMOVAL

Preparation

Remove air dam using power tool.

Remove engine undercover using power tool.

Drain the engine coolant. Refer to

CO-39, "Changing Engine Coolant"

Rear engine mounting insulator 4WD 2.

Rear engine mounting insulator 2WD 3.

LH engine mounting bracket

LH heat shield plate

LH engine mounting insulator

RH engine mounting bracket

RH heat shield plate

RH engine mounting insulator

LBIA0397E

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